The basic image-forming process of photography comprises the exposure of a silver halide photographic recording material, such as a color film, to electromagnetic radiation, and the chemical processing of the exposed material to provide a useful image. Chemical processing involves one fundamental step and one or more ancillary steps. The fundamental step is treatment of the exposed silver halide material with a developing agent wherein some or all silver ion is reduced to metallic silver, and in the case of color materials, a dye image is formed (because of a color developing agent).
For color materials, ancillary steps include the removal of silver metal and silver salts by one or more steps of bleaching and fixing so that only a dye image remains in the processed material. These steps are commonly used to enable optical printing and can make scanning easier. During bleaching, the developed silver is oxidized to a silver salt by a suitable bleaching agent. The oxidized silver is then dissolved and removed from the material using a "fixing" agent or silver solvent in a fixing step. Black-and-white materials are desilvered using only the fixing step.
Additional photoprocessing steps may be needed including rinsing or dye stabilization that requires even more photoprocessing chemicals. In the case of color reversal materials, additional photoprocessing steps include black-and-white development, a reversal step, pre-bleaching or conditioning step and one or more rinsing steps.
All of these photoprocessing steps require preparation of the photoprocessing compositions (whether in aqueous or solid form), large or small photoprocessing tanks or reservoirs to hold the compositions, and disposal or regeneration of the "spent" compositions once a predetermined amount of exposed material has been processed. All of these operations require considerable manufacturing effort, shipping and handling of chemicals and aqueous solutions, replenishment of the solutions, and disposal of solutions into the environment. These characteristics of conventional photoprocessing are labor intensive, tedious, costly and potentially harmful to the environment (although much work has been accomplished in the industry to make the compositions more environmentally "friendly").
New business opportunities are thought to exist if ways can be found to minimize or obviate the problems described above. Providing photographic images (often known as "photofinishing") is a growing business and yet there is a need to provide those images in ways that do not require some or all of the traditional photoprocessing solutions, equipment and replenishment systems.
Various research efforts have been carried out in the industry to provide new methods of imaging. For example, research has been carried out directed at putting photoprocessing chemicals directly into the imageable materials. Coated donor/receivers systems on flexible supports have been developed in recent decades for output media (such as color prints). The conventional "instant" photographic materials are examples of imaging materials that include coated and/or delivered photoprocessing chemicals. See for example, U.S. Pat. No. 4,605,608 (Bullitt).
U.S. Pat. No. 5,453,804 (Norris et al) describes a hydrogel, rolled flexible carried material that comprises an aqueous, alkaline processing composition that is used in an image transfer processing method. This material does not include a backing sheet or non-porous supporting substrate.
All of the ongoing research efforts still have some unattractive features pertaining to the delivery of the photoprocessing chemicals (identified as "photochemicals" hereinafter). To date, the need for enabling technology remains unsatisfied.
Photoprocessing webs comprised of gelatin or other hydrophilic colloids are also known as described for example in U.S. Pat. No. 3,179,517 (Tregillus et al).
In order to simplify the mechanical requirements of photoprocessing, it would be desirable to avoid high precision fluid spreading that may be required in extrusion hopper metering or a fluid bath for coating materials to be laminated. Thus, there continues to be a need for a unique means for photoprocessing that is not accompanied by the problems noted above with traditional methods or known research methods.